4.Queue and Stack: 1ts points that implements a queue by using two stacks, which are called inStack and outStack . Push the new element ceto inStack Dequeue . If outStack is empty, refill it by popping each element from inStack and pushing it onto outStack Pop and return the pop clement from outStack (1) Given the partial implementation QueueU singStacks class, please complete thres size), isEmpty0 and dequeuer) below Note ArrayStack class contains methods: popl assume the two stacks are never full (with infinite space). push(Object e), size) and isEmpty0. You can public final class private ArrayStack inStack new ArrayStack): private ArrayStack outstack mew ArrayStack) public void enqueue (Objecte) inStack.push(e)i public int size) t public boolean isEepty) (